1. Field of the Invention
The present invention relates to an optical pickup, more particularly to an optical pickup having a tilting function.
2. Description of the Related Art
In an optical pickup disclosed in JP-A-2002-92916 (pp. 3-4, FIG. 1), an opening is provided in a lens holder body. A flat panel including a focusing coil, a tracking coil, and a tilt coils is mounted in such a manner as to traverse and divide the opening into two. A pair of magnets are disposed in the opening so as to oppose to each other with the flat panel placed therebetween. In this optical pickup, a magnet for tilting is omitted by effecting focusing, tracking, and lens tilting adjustment by the common magnets.
In an optical pickup disclosed in JP-A-2002-140828 (pp. 4-10, FIG. 1), two openings are provided in the lens holder body on both sides of an objective lens, a pair of flat panels each including a focusing coil and a tracking coil are respectively mounted on outer wall surfaces adjacent to the respective openings. Further, a pair of magnets opposing to each other so as to sandwich the respective flat panels are disposed in the openings and on the outer sides of the flat panels. In this optical pickup, lens tilting adjustment is effected by the focusing coil and the tracking coils in the two magnetic circuits, and the magnet for tilting is omitted.
In the optical pickup disclosed in JP-A-2002-92916, since the pair of magnets are disposed in the opening of the lens holder body, it is necessary to form the lens holder body with a large size. In addition, since the opening is formed, the rigidity of the lens holder body is low. Furthermore, since a substantially closed magnetic circuit is formed by the pair of magnets opposing to each other with the flat panel placed there between, an increase in the secondary resonance frequency of the lens holder body is hampered, there by preventing attainment of high speed operation.
In the optical pickup disclosed in JP-A-2002-140828, since the arrangement provided is such that two openings are provided in the lens holder body, and the magnets are respectively disposed therein, it is necessary to form the lens holder body with a large size. Further, since the openings are formed, the rigidity of the lens holder body is low. Furthermore, since a substantially closed magnetic circuit is formed by the pair of magnets opposing to each other, an increase in the secondary resonance frequency of the lens holder body is hampered, thereby preventing attainment of high speed operation.